diff --git a/docs/Configuration.md b/docs/Configuration.md index 3d3d3ba456..9be09ee6b6 100644 --- a/docs/Configuration.md +++ b/docs/Configuration.md @@ -132,22 +132,6 @@ set telemetry_provider = 1 save ``` -## FrSky telemetry - -FrSky telemetry signals are inverted. To connect a cleanflight capable board to an FrSKy receiver you have some options. - -1. A hardware inverter - Built in to some flight controllers. -2. Use software serial and enable frsky_inversion. -3. Use a flight controller that has software configurable hardware inversion (e.g. STM32F30x). - -For 1, just connect your inverter to a usart or software serial port. - -For 2 and 3 use the cli command as follows: - -``` -set frsky_inversion = 1 -``` - ## CLI command differences from baseflight ### gps_type diff --git a/docs/Telemetry.md b/docs/Telemetry.md new file mode 100644 index 0000000000..8a5d8924d3 --- /dev/null +++ b/docs/Telemetry.md @@ -0,0 +1,49 @@ +# Telemetry + +Telemetry allows you to know what is happening on your aircraft while you are flying it. Among other things you can receive battery voltages and GPS positions on your transmitter. + +Two telemetry providers are currently supported, FrSky (the default) and Graupner HoTT V4. + +## FrSky telemetry + +See the Configuration examples in the documentation for details on how to enable it. + +FrSky telemetry is transmit only and just requires a single connection from the TX pin of a serial port to the RX pin on an FrSky telemetry receiver. + +FrSky telemetry signals are inverted. To connect a cleanflight capable board to an FrSKy receiver you have some options. + +1. A hardware inverter - Built in to some flight controllers. +2. Use software serial and enable frsky_inversion. +3. Use a flight controller that has software configurable hardware inversion (e.g. STM32F30x). + +For 1, just connect your inverter to a usart or software serial port. + +For 2 and 3 use the cli command as follows: + +``` +set frsky_inversion = 1 +``` + +## HoTT telemetry + +See the Configuration examples in the documentation for details on how to enable it. + +HoTT telemetry can be used when the TX and RX pins of a serial port are connected using a diode and a single wire to the T port on a HoTT receiver. + +Serial ports use two wires but HoTT uses a single wire so some electronics are required so that the signals don't get mixed up. + +Connect as follows: +``` +HoTT TX/RX -> Serial RX (connect directly) +Serial TX -> 1N4148 Diode -(| )-> HoTT TX/RX (connect via diode) +``` + +The diode should be arranged to allow the data signals to flow the right way + +``` +-(| )- == Diode, | indicates cathode marker. +``` + +As noticed by Skrebber the GR-12 (and probably GR-16/24, too) are based on a PIC 24FJ64GA-002, which has 5V tolerant digital pins. + +Note: The softserial ports are not listed as 5V tolerant in the STM32F103xx data sheet pinouts and pin description section. Verify if you require a 5v/3.3v level shifters.